JP6986751B2 - Column-beam joint structure - Google Patents

Description

The present invention is composed of a column portion made of a cold roll-formed square steel pipe, a beam portion made of H-shaped steel, and a hot-formed square steel pipe, and the connection between the column portion and the beam portion. It relates to a beam-column joint structure including a non-diaphragm type joint portion as a part.

Conventionally, this type of beam-column joint structure is configured by welding and joining a plurality of steel pipes, and at that time, there are joining types such as a through diaphragm type and an inner diaphragm type as welding joints.
However, according to the joining type such as the through diaphragm type and the inner diaphragm type, there is a problem that the whole work is complicated because the assembly man-hours (welding points) are large and the welding length is long.

Therefore, as a solution to such a problem, a non-diaphragm type column-beam joint using a thick short square steel pipe formed by hot forming at the joint part that is the connection part between the column part and the beam part. Structures are provided (eg, Patent Document 1). That is, a long square steel pipe having a predetermined plate thickness and a semi-formed short square steel pipe having a thickness thicker than this long square steel pipe and having a length forming a joint portion are manufactured by cold forming, respectively. Then, after heating the semi-formed short square steel pipe in a heating furnace, hot forming is performed to manufacture the short square steel pipe. A square steel pipe column is obtained by welding and joining the long square steel pipe and the short square steel pipe thus obtained by arc welding or the like.
According to the column-beam joint structure using the thick short square steel pipe obtained by such hot forming, the assembly man-hours can be reduced, the welding length can be shortened, and the entire work can be simplified.

Japanese Unexamined Patent Publication No. 2003-268877

However, in the beam-column joint structure of Patent Document 1, when an external force due to an earthquake or the like is applied to the joint portion that is the connection portion between the column portion and the beam portion, a large stress or strain is concentrated on the joint end portion of the beam portion. The joint end of the beam may be damaged or the joint may be deformed by pushing the beam. Then, in a non-diaphragm type frame such as the column-beam joint structure of Patent Document 1, the deformation of the joint portion is compared with the deformation of the joint portion that occurs in the through diaphragm type frame or the inner diaphragm type frame. There is a problem that it is big. That is, in a non-diaphragm type frame such as the beam-column joint structure of Patent Document 1, there is a problem that the rigidity thereof is smaller than the rigidity of the through-diaphragm type frame or the inner diaphragm type frame.

Therefore, an object of the present invention is to provide a beam-column joint structure having the same rigidity as a through-diaphragm type frame or an inner diaphragm type frame in a non-diaphragm type frame.

The problem to be solved by the present invention has been described above, and next, the means for solving this problem will be described.

That is, the beam-column welded structure of the present invention has a beam portion made of H-shaped steel having a pillar portion made of a cold roll-formed square steel pipe, a pair of flanges, and a web connecting the flanges. A beam-column joint structure including a non-diaphragm type welded portion which is composed of a hot-formed square steel pipe and serves as a connecting portion between the pillar portion and the beam portion, and both sides of the joint portion. The pillar portion is welded to the end surface of the open end portion in the above section, and a quadrangular reinforcing plate is welded to the inside of the open end portions at both ends so as to be flush with the end surface of the open end portion. The beam portion is formed so that one end side of the flange is shorter than the one end side of the web, and the end surface of the one end side of the flange and the joint portion are formed by the beam portion welded to the side surface of the joint portion. A flat plate-shaped horizontal haunch is provided in the gap formed between the side surface of the beam, and one end surface of the horizontal haunch is welded to the end surface on one end side of the flange, and the other end faces are each of both ends thereof. , Arranged at an intermediate position between the apex of the corner portion of the joint portion and the R stop of the corner portion including the apex, welded to the side surface of the joint portion, and the horizontal haunch is welded and joined. The gap between the end surface on one end side of the flange and the side surface of the weld is formed based on the difference between the outer diameter of the weld and the width of the flange.

In the beam-column joint structure of the present invention, in the above-mentioned column-beam joint structure, the ratio of the outer diameter B of the column portion to the plate thickness tp of the joint portion is 10 ≦ B / in the column portion and the joint portion. It is molded so that tp ≦ 15, and the outer radius of curvature of the corner portion of the joint portion is formed to be 1.5 to 2.5 times the plate thickness of the joint portion.

According to the beam-column joint structure of the present invention, in the gap between the end surface on one end side of the flange formed based on the difference between the outer diameter of the joint portion and the width of the flange, and the side surface of the joint portion. Since the flat plate-shaped horizontal haunch is provided, the rigidity of the frame can be increased, and a non-diaphragm type frame having the same rigidity as the through-diaphragm type frame or the inner diaphragm type frame can be constructed. In the structural design of a building that adopts the non-diaphragm type, the beam end of the beam can be modeled as a rigid joint.

It is a partially cutaway perspective view of the main part of the column-beam joint structure which concerns on this invention. It is a vertical sectional front view of the main part of the column-beam joint structure which concerns on this invention. It is a cross-sectional plan view of the main part of the column-beam joint structure which concerns on this invention. It is a chart of suitability of the combination of the column shaft and the joint core of the column-beam joint structure which concerns on this invention. It is a top view which shows the overlap of the column shaft of the column-beam joint structure which concerns on this invention, and the joint core. It is a schematic diagram which shows the analysis model of the column-beam joint structure used for FEM analysis. (A) is a schematic diagram of the General Yield method used for FEM analysis, and (b) is a load deformation curve obtained from the result of FEM analysis. It is a Mises stress diagram at the time of the total plastic proof stress of the comparative example 1, (a) is a figure which shows the appearance, (b) is the figure which shows the inside view. It is a Mises stress diagram at the time of the final step (R = 1/10 rad) of the comparative example 1, (a) is the figure which shows the appearance, (b) is the figure which shows the inside. It is a Mises stress diagram at the time of the total plastic proof stress of the comparative example 2, (a) is the figure which shows the appearance, (b) is the figure which shows the inside view. It is a Mises stress diagram at the time of the final step (R = 1/10 rad) of the comparative example 2, (a) is the figure which shows the appearance, (b) is the figure which shows the inside. It is a Mises stress diagram at the time of the total plastic proof stress of the comparative example 3, (a) is a figure which shows the appearance, (b) is the figure which shows the inside view. It is a Mises stress diagram at the time of the final step (R = 1/10 rad) of the comparative example 3, (a) is the figure which shows the appearance, (b) is the figure which shows the inside. It is a Mises stress diagram at the time of total plastic proof stress of Example 1, (a) is the figure which shows the appearance, (b) is the figure which shows the inside view. It is a Mises stress diagram at the time of the final step (R = 1/10 rad) of Example 1, (a) is the figure which shows the appearance, (b) is the figure which shows the inside.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the column-beam joint structure 10 according to the present invention will be described. The present invention is not limited to the beam-column joint structure 10 described below.

As shown in FIG. 1, the beam-column joint structure 10 is arranged between the upper and lower column shafts 11A and 11B (an example of the “column portion”) extending in the vertical direction and the upper and lower column shafts 11A and 11B. The joint core 12 (an example of the "joint portion") and the beam 13 ("beam portion") having one end fixed to the outer surface of the joint core 12 facing four sides and extending in the horizontal direction. One example) and.

As shown in FIGS. 1 to 3, the upper and lower column shafts 11A and 11B are long square steel pipes cold roll-formed by forming means such as a breakdown device and a finpass device. The upper and lower column shafts 11A and 11B have an outer diameter B of 200 mm to 550 mm and a plate thickness tc of 9 mm to 25 mm. The upper and lower column shafts 11A and 11B are formed so that the outer radius of curvature of the corner portion 11a is 2.0 to 3.0 times the plate thickness ct of the upper and lower column shafts 11A and 11B. As shown in FIG. 2, the upper and lower column shafts 11A and 11B are formed with a groove portion 11b having a predetermined angle by cutting the outer portion of the end portion of the upper and lower column shafts 11A and 11B by a processing means such as a cutting apparatus. The upper and lower column shafts 11A and 11B are fixed by welding 16 with a square ring-shaped backing metal 15 internally fitted at the end thereof.

The joint core 12 is a short square steel pipe that is heated by a heating means such as a heating furnace and hot-formed by a forming means such as a forming roll device. As shown in FIGS. 1 to 3, the joint core 12 is a connection portion between the upper and lower column shafts 11A and 11B and the beam 13, and is configured in a non-diaphragm type. The joint core 12 is formed so that the length L in the longitudinal direction (vertical direction) is longer than the height D (height between the flanges 13a) of the beams 13 to be welded and joined. The joint core 12 has an outer diameter Bp of 220 mm to 575 mm and a plate thickness tp of the panel 12a of 19 mm to 50 mm. The joint core 12 is formed so that the outer radius of curvature of the corner portion 12b is 1.5 to 2.5 times the plate thickness tp of the panel 12a of the joint core 12. Here, the outer radius of curvature of the corner portion 12b of the joint core 12 is an angle of 45 degrees with the side orthogonal to the adjacent inner and outer surfaces of the joint core 12 as shown in FIG. 5 (a). The radius of curvature at the intersection of the line forming the line and the outer corner of the corner portion 12b.

As shown in FIGS. 1 and 2, in the beam-column joint structure 10, the upper and lower column shafts 11A and 11B and the joint core 12 are formed so as to be positioned linearly. Specifically, the lower end portion of the joint core 12 is arranged at the upper end portion of the lower pillar shaft 11B, and the upper end portion of the joint core 12 is arranged at the lower end portion of the upper pillar shaft 11A. Then, in a state where the outer surface of the backing metal 15 located inside the upper and lower pillar shafts 11A and 11B is in contact with the end surface 12c of the panel 12a of the joint core 12, the upper and lower pillar shafts 11A and 11B are welded. The mouth core 12 is joined from the outside by welding 17. In the beam-column joint structure 10, the outer diameter Bp of the joint core 12 is the upper and lower column shafts 11A and 11B so that the end faces of the upper and lower column shafts 11A and 11B can be placed on the end face 12c of the joint core 12. It is set to be longer than the outer diameter B of the above by a predetermined length.

As shown in FIGS. 1 to 3, the beam 13 is formed of H-shaped steel and is composed of two flat plate-shaped flanges 13a facing each other and a web 13b formed between the facing flanges 13a. To. The beam 13 is welded to the joint core 12 so that the flange 13a faces vertically and one end surface of the web 13b abuts along the panel 12a of the joint core 12.

The flange 13a has a groove portion 13c formed on one end side in the longitudinal direction thereof, and one end side on which the groove portion 13c is formed corresponds to one end side in the longitudinal direction of the web 13b (the panel 12a of the joint core 12). It is formed shorter than the contacting side). That is, the flange 13a is formed so that its length in the longitudinal direction is shorter than the length in the longitudinal direction of the web 13b. Since one end side of the flange 13a is formed shorter than one end side of the web 13b, when the beam 13 is welded to the panel 12a (the side surface of the joint core 12), the end surface of the flange 13a and the panel 12a ( A gap K is formed between the side surface of the joint core 12). That is, the gap K is formed at the beam end on the welded joint side of the beam 13 with the panel 12a.

The gap K is a horizontal gap from the tip of the groove portion 13c on one end side of the flange 13a to the side surface of the panel 12a to which the beam 13 is welded and joined when the beam 13 is welded and joined to the panel 12a. It is formed based on the difference (Bp-W) between the outer diameter Bp of the mouth core 12 and the width W of the flange 13a (the length in the direction horizontally orthogonal to the longitudinal direction of the flange 13a). That is, the gap K is formed wider as the width W of the flange 13a becomes shorter than the outer diameter Bp of the joint core 12, and the gap K is formed narrower as the width W of the flange 13a approaches the outer diameter Bp of the joint core 12. To.

As shown in FIGS. 1 to 3, in the column-beam joint structure 10, between the end surface on one end side of the flange 13a and the side surface of the joint core 12 by the beam 13 welded to the side surface of the joint core 12. A horizontal haunch 30 is provided in the gap K formed in. One end surface of the horizontal haunch 30 is welded to the end surface on one end side of the flange 13a, and the other end surface is welded to the panel 12a (side surface of the joint core 12). Specifically, the horizontal haunch 30 and the flange 13a are joined by welding 32 with the backing metal 31 in contact with one end side of the horizontal haunch 30 and one end side of the flange 13a. Further, the horizontal haunch 30 and the panel 12a are joined by welding 34 with the backing metal 33 in contact with the other end side of the horizontal haunch 30 and the side surface (panel 12a) of the joint core 12.

The horizontal haunch 30 is composed of a flat plate-shaped member. The horizontal haunch 30 is formed in a substantially rectangular shape, and the length in the width direction (the length in the direction horizontally orthogonal to the longitudinal direction of the horizontal haunch 30) is set corresponding to the length of the gap K. .. The length of the horizontal haunch 30 in the longitudinal direction is longer than the length in the width direction of the flat plate portion on the side surface of the joint core 12 (the length between the _{two R stops R0 at both ends of each side surface of the joint core 12).} It is set a little longer. Specifically, horizontal haunch 30, when the other end face is welded to the side surface of the Joint core 12, each of its ends, the vertex R ₁ of the corner portions 12b of the Joint core 12, the apex and R blind R ₀ of corner portions 12b containing R _1, the intermediate position R ₂ placeable length _(apex R ₁ and R blind curve intermediate position between the R _0), in the longitudinal direction The length is set. Here, as shown in FIG. 3, the vertex R ₁ of the corner portions 12b of the Joint core 12, intersection between diagonal lines T of the outer diameter side surface and the Joint core 12 of the corner portion 12b of the Joint core 12 Refers to the position. Further, the R stop R ₀ of the corner portion 12b is a position on the outer diameter side surface of the corner portion 12b where the curved portion of the corner portion 12b ends (the position where the flat plate portion on the side surface of the joint core 12 starts). ).

A horizontal stiffener 18 (an example of a "reinforcing plate material") is welded to the inside of both end portions of the joint core 12. The horizontal stiffener 18 is a rectangular metal flat plate having an inner diameter of the joint core 12. The horizontal stiffener 18 is arranged so that its flat surface portion is flush with the end surface 12c of the panel 12a of the joint core 12, and is welded to the inner surface of the joint core 12 so as to close the openings on both sides of the joint core 12. Be joined. That is, the horizontal stiffener 18 is different from the inner diaphragm, and like the inner diaphragm, the flange 13a of the beam 13 which is inside the joint core 12 and whose flat surface portion is fixed to the joint core 12 It is not arranged so as to be flush with the flat surface portion, but is arranged on the end surface 12c side of the panel 12a of the joint core 12 from the flat surface portion of the flange 13a of the beam 13. By providing the horizontal stiffeners 18 inside both end portions of the joint core 12, it is possible to prevent the panel 12a of the joint core 12 from being deformed by pushing the beam 13, and from the end surface 12c of the panel 12a of the joint core 12. The height X (extra length of the joint core 12) between the upper and lower surfaces of the flange 13a of the beam 13 can be shortened. Specifically, by providing the horizontal stiffeners 18 inside both end portions of the joint core 12, the extra length of the joint core 12 can be set to (outer diameters B of the upper and lower pillar shafts 11A and 11B) / 4. can.

When welding the horizontal stiffener 18 to the joint core 12, first, both sides of the joint core 12 so that the flat surface portion of the horizontal stiffener 18 is flush with the end surface 12c of the panel 12a of the joint core 12. Place in the opening of. Then, with the horizontal stiffener 18 arranged in the openings on both sides of the joint core 12, the end portion of the panel 12a on the end surface 12c side and the outer end portion of the horizontal stiffener 18 (upper and lower pillar shafts 11A and 11B are provided. The side end) and are cut to a predetermined thickness in the width direction of the joint core 12. By cutting the panel 12a and the horizontal stiffener 18 in this way, the flat surface portion of the horizontal stiffener 18 and the end surface 12c of the panel 12a of the joint core 12 become more accurately flush with each other, and the backing metal 15 can be mounted accurately. It can be done well and easily.

Next, a method of selecting the upper and lower column shafts 11A and 11B and the joint core 12 will be described.
When selecting the upper and lower column shafts 11A and 11B and the joint core 12 to be used in the beam-column joint structure 10, first, the outer diameter B of the upper and lower column shafts 11A and 11B and the outer diameter Bp of the joint core 12 are set. .. In the beam-column joint structure 10, the outer diameters B and the joint core 12 of the upper and lower column shafts 11A and 11B are placed so that the end faces of the upper and lower column shafts 11A and 11B are placed on the end face 12c of the joint core 12. The outer diameter Bp of is set. Specifically, the outer diameter Bp of the joint core 12 is set to be longer than the outer diameters B of the upper and lower column shafts 11A and 11B, and the columns are used by using the upper and lower column shafts 11A and 11B having an outer diameter of 200 mm to 350 mm. When the beam joining structure 10 is formed, the upper and lower column shafts 11A and 11B having an outer diameter Bp of 400 mm to 550 mm are used by using a joint core 12 whose outer diameter Bp is 20 mm longer than the outer diameter B of the upper and lower column shafts 11A and 11B. When the column-beam joint structure 10 is formed using the above, a joint core 12 whose outer diameter Bp is 25 mm longer than the outer diameter B of the upper and lower column shafts 11A and 11B is used.

When the outer diameters B of the upper and lower column shafts 11A and 11B and the outer diameter Bp of the joint core 12 are set, the plate thickness ct of the upper and lower column shafts 11A and 11B and the plate thickness tp of the panel 12a of the joint core 12 are set. Set. Specifically, based on the table of FIG. 4, it is determined whether or not the combination of the plate thickness cts of the upper and lower column shafts 11A and 11B and the plate thickness tp of the panel 12a of the joint core 12 is appropriate. The suitability of the combination of the plate thickness ct of the upper and lower column shafts 11A and 11B and the plate thickness tp of the panel 12a of the joint core 12 depends on the outer diameter B of the upper and lower column shafts 11A and 11B and the plate thickness of the joint core 12. Judgment is made based on the applicable range in which the ratio to tp is 10 ≦ B / tp ≦ 15. That is, it is determined whether or not the combination of the plate thickness ct of the upper and lower column shafts 11A and 11B and the plate thickness tp of the panel 12a of the joint core 12 is within the applicable range. The circles in the table shown in FIG. 4 indicate that the combination of the plate thickness tk of the upper and lower column shafts 11A and 11B and the plate thickness tp of the panel 12a of the joint core 12 is within the applicable range, and the upper and lower columns are in the applicable range. This means that the joints between the shafts 11A and 11B and the joint core 12 do not have a cross-sectional discrepancy. On the other hand, the x mark in the table shown in FIG. 4 indicates that the combination of the plate thickness ct of the upper and lower column shafts 11A and 11B and the plate thickness tp of the panel 12a of the joint core 12 is out of the applicable range. This means that there is a discrepancy in cross section between the column shafts 11A and 11B of No. 1 and the joint core 12 of the above.

Specifically, when the outer diameter B of the upper and lower column shafts 11A and 11B is set to 250 mm and the outer diameter Bp of the joint core 12 is set to 270 mm, it is combined with the upper and lower column shafts 11A and 11B having a plate thickness tc of 9 mm. The possible joint core 12 is a joint core 12 having a plate thickness tp of the panel 12a of 19 mm, 22 mm, and 25 mm. Similarly, when the outer diameter B of the upper and lower column shafts 11A and 11B is set to 250 mm and the outer diameter Bp of the joint core 12 is set to 270 mm, it can be combined with the upper and lower column shafts 11A and 11B having a plate thickness ct of 12 mm. The joint core 12 is a joint core 12 having a plate thickness tp of the panel 12a of 22 mm and 25 mm, and the joint core 12 having a plate thickness tp of the panel 12a of 19 mm cannot be combined.
In this way, after setting the outer diameter Bp of the joint core 12 to be longer than the outer diameter B of the upper and lower column shafts 11A and 11B, the plate thickness ct of the upper and lower column shafts 11A and 11B and the joint By setting the combination of the core 12 with the plate thickness tp of the panel 12a within the above applicable range, the column-beam joint structure 10 has the outer diameters B of the upper and lower column shafts 11A and 11B and the plate thickness tp of the joint core 12. It is formed so that the ratio with and to is 10 ≦ B / tp ≦ 15, and the outer radius of curvature of the corner portion 12b of the joint core 12 is set to the outer diameter of the outer radius of the corner portions 11a of the upper and lower column shafts 11A and 11B. It is formed so that the end faces of the upper and lower column shafts 11A and 11B are placed on the end face 12c of the joint core 12 without increasing the size.
Specifically, when the upper and lower column shafts 11A and 11B having an outer diameter B of 400 mm and a plate thickness ct of 16 mm or 19 mm are used, the outer diameter Bp is 425 mm longer than the outer diameter B of the column shafts 11A and 11B. If a joint core 12 having a panel thickness tp of 32 mm to 40 mm is used, the end faces of the upper and lower column shafts 11A and 11B are the joints as shown in FIGS. 5A and 5B. It is molded so as to be placed on the end face 12c of the core 12. When the upper and lower column shafts 11A and 11B having an outer diameter B of 450 mm and a plate thickness tc of 22 mm are used, the outer diameter Bp is 475 mm longer than the outer diameter B of the column shafts 11A and 11B. If a panel 12a having a plate thickness tp of 36 mm to 45 mm is used, the end faces of the upper and lower column shafts 11A and 11B are placed on the end face 12c of the joint core 12 as shown in FIG. 5 (c). It is molded to be. Further, when the upper and lower column shafts 11A and 11B having an outer diameter B of 500 mm and a plate thickness tc of 25 mm are used, the outer diameter Bp is 525 mm longer than the outer diameter B of the column shafts 11A and 11B. If a panel 12a having a plate thickness tp of 40 mm to 50 mm is used, the end faces of the upper and lower column shafts 11A and 11B are placed on the end faces 12c of the joint core 12 as shown in FIG. 5 (d). It is molded to be.

Next, since the effect of the present invention was confirmed by FEM analysis, this will be described in the following examples.

In the following examples, the upper and lower pillar shafts 11A, 11B and □ -400 × 400 × 16 (R = 40) in the beam-column joint structure 10, proof stress 324.5N / mm ^2, a tensile strength of 400 N / ^mm 2, It is composed of cold roll-formed square steel pipes with F value 295N / mm ² , E value 205000N / mm ² , ν value 0.3, and BCR295, and the beam 13 is H-488 × 300 × 11 × 18, withstand strength 258.5N. / Mm ² , tensile strength ^{400N / mm 2} , F value 235N / mm ² , E value 205000N / mm ² , ν value 0.3, SN400B through-diaphragm type or non-diaphragm type cross FEM analysis was performed on the overhead groove (test piece).

Further, a cross-shaped frame (test piece) having a beam-column joint structure 10 formed in a diaphragm type is used as Comparative Example 1, and a cross-shaped frame (test piece) having a beam-column joint structure 10 formed in a non-diaphragm type is compared. Example 2, Comparative Example 3, and Example 1.

Incidentally, the panel 12a of the Joint core 12 in Comparative Example 1 of the diaphragm type, □ -400 × 400 × 16 ( R = 40), yield strength 324.5N / mm ^2, a tensile strength of 400 N / ^mm 2, F value 295N / ^mm 2, E value 205000N / mm ^2, ν value 0.3, constituted by RHS cold roll forming of BCR295, diaphragm yield strength 357.5N / mm ^2, a tensile strength of 490 N / ^mm 2, F value 325N / ^mm 2, E value 205000N / mm ^2, ν value 0.3, was composed of plate material SN490C.

Further, the panel 12a of the joint core 12 in Comparative Example 2, Comparative Example 3 and Example 1 of the non-diaphragm type has □ 425 × 425 × 32 (R = 64), proof stress 357.5 N / mm ² , and tensile strength. is 490 N / ^mm 2, F value 325N / ^mm 2, E value 205000N / mm ^2, ν value 0.3, constituted by RHS of hot forming of SHC490C, horizontal stiffener 18, yield strength 357.5N / mm ² , Tensile strength 490N / mm ² , F value ^{325N / mm 2} , E value 205000N / mm ² , ν value 0.3, SN490B, and the extra length of the panel 12a is (upper and lower column shafts 11A, The outer diameter of 11B was set to B) / 4.

Further, in Comparative Example 2 of the non-diaphragm type, the horizontal stiffeners 18 are welded and joined to the insides of both end portions of the panel 12a, and in Comparative Example 3, the horizontal stiffeners 18 are welded and joined to the insides of both end portions of the panel 12a. It is assumed that two horizontal stiffeners 18 are installed in the middle portion of the panel 12a, and in the first embodiment, the horizontal stiffeners 18 are welded and joined to the inside of both end portions of the panel 12a, and the beam 13 is connected to the panel 12a (joint core). It is assumed that the horizontal haunch 30 is installed in the gap K formed at the time of welding and joining to the side surface of 12).

As shown in FIG. 6, in this example, the test body was modeled with a 1/2 symmetry model. The panel 12a, the upper and lower column shafts 11A and 11B, and the beam 13 are modeled with an 8-node solid element (complete integration element) from the member end to the member center, and a 2-node beam element (linear material element) from the member center to the member tip. ) Modeled. For the connection between the beam element and the solid element, the beam element end contact was set as an independent node and the solid element face node was set as a dependent node so that the plane holding was established at the connection position. As a constraint condition, the solid element part restrains the _{displacement in the out-of-plane direction on the plane of symmetry (Uz} = 0), and the beam element part restrains the out-of-plane displacement, the rotation in the out-of-plane direction, and the torsional rotation (U z = 0). _z = 0, θ _x = 0, θ _y = 0), the tip of the beam element other than the force point is supported by a roller that is free in the material axis direction (beam 13: U _y = 0, upper and lower column shafts 11A, 11B). : U _x = 0). In consideration of the material geometric non-linearity, the analysis was an incremental analysis by displacement control at the tip position of the upper column shaft 11A (up to 1/10 rad in the interlayer deformation angle).

The total plastic strength in the FEM analysis results shown in FIGS. 7 and 1 was calculated by the General Yield method (FIG. 7 (a)).

In FIGS. 8 to 15, only the range in which the Mises stress criterion is 235 N / mm ² or more (excellent stress) is displayed as a pattern.

As shown in FIG. 7B and Table 1, the ultimate proof stress including the total plastic proof stress was almost the same regardless of the test pieces of Comparative Examples 1 to 3 and Example 1. In this way, the proof stress of each test piece is almost the same as that of the beam leading yield type collapse type in which the proof stress of the frame is determined by the bending strength of the beam 13 in common for each test piece. This is because.

As shown in Table 1, the test piece of Comparative Example 2 (a non-diaphragm type frame in which the horizontal stiffeners 18 are provided only inside both end portions (top portion and bottom portion) of the panel 12a) is the test piece of Comparative Example 1. (Through diaphragm type frame) The rigidity is smaller than that. Further, the test piece of Comparative Example 3 (a non-diaphragm type frame in which horizontal stiffeners 18 are welded and joined inside both end portions of the panel 12a and two horizontal stiffeners 18 are installed in the middle portion of the panel 12a) is compared. The rigidity was almost the same as that of the test piece of Example 1 (through diaphragm type frame).

As can be seen from the comparison of the stress generated in the horizontal stiffener 18 from FIGS. 10 and 11 (Comparative Example 2) and FIGS. 12 and 13 (Comparative Example 3), the rigidity of Comparative Example 3 is higher than that of Comparative Example 2. The increase (the rigidity of Comparative Example 3 was almost the same as that of Comparative Example 1) is due to the action of the horizontal stiffener 18 provided in the middle portion of the panel 12a.

Further, the gap K formed when the test piece of Example 1 (horizontal stiffness 18 is welded and joined to the inside of both end portions of the panel 12a and the beam 13 is welded and joined to the panel 12a (side surface of the joint core 12)). The non-diaphragm type frame in which the horizontal haunch 30 was installed was as rigid as the test piece of Comparative Example 1 (through-diaphragm type frame) as in Comparative Example 3.

As can be seen from the comparison of the stress generated in the panel 12a from FIGS. 10, 11 (Comparative Example 2), 14 and 15 (Example 1), the rigidity of Example 1 is the same as that of Comparative Example 3. Similarly, the rigidity of Comparative Example 1 was almost the same (the rigidity of Example 1 became larger than the rigidity of Comparative Example 2) by providing the horizontal haunch 30 in the gap K (beam end). This is because the stress generated in the panel 12a is reduced and the out-of-plane deformation of the side surface of the panel 12a is reduced.

As described above, in the beam-column joint structure 10, the end face on one end side of the flange 13a formed based on the difference (Bp-W) between the outer diameter Bp of the joint core 12 and the width W of the flange 13a. Since the flat plate-shaped horizontal haunch 30 is provided in the gap K (the beam end on the welded joint side of the beam 13 with the panel 12a) between the side surface (panel 12a) of the joint core 12, the rigidity of the frame is increased. It is possible to construct a non-diaphragm type frame having the same rigidity as a through-diaphragm type frame or an inner diaphragm type frame. That is, in the structural design of a building adopting the non-diaphragm type, the beam end portion of the beam 13 can be modeled as a rigid joint and the structural calculation can be performed.

In the beam-column joint structure 10, the rigidity of the frame can be increased by providing the horizontal stiffener 18 in the middle portion of the panel 12a in addition to the inside of both end portions of the panel 12a, and the frame or the inside of the through diaphragm type frame. It is possible to construct a non-diaphragm type frame having the same rigidity as the diaphragm type frame. That is, in the structural design of a building adopting the non-diaphragm type, the beam end portion of the beam 13 can be modeled as a rigid joint and the structural calculation can be performed.

10 Column-beam joint structure 11A, 11B Column shaft (column part)
12 Joint core (joint part)
12b Corner part 13 Beam (beam part)
13a Flange 13b Web 18 Horizontal stiffener (reinforcing plate material)
30 Horizontal haunch Bp Outer diameter of joint core K Gap R ₀ R Stop R ₁ Vertex R ₂ Intermediate position W Flange width

Claims (2)

Columns made of cold roll-formed square steel pipes,
A beam portion made of H-section steel having a pair of flanges and a web connecting the flanges.
A non-diaphragm type joint portion that is composed of hot-formed square steel pipes and serves as a connecting portion between the column portion and the beam portion.
It is a column-beam joint structure equipped with
The pillars are welded to the end faces of the open ends on both sides of the joint, and a square reinforcing plate material is flush with the end faces of the open ends inside the open ends at both ends. Welded and joined so that
The beam portion is formed so that one end side of the flange is shorter than the one end side of the web.
A flat plate-shaped horizontal haunch is provided in the gap formed between the end surface on one end side of the flange and the side surface of the joint portion by the beam portion welded to the side surface of the joint portion.
The horizontal haunch is
One end surface thereof is welded and joined to the end surface on one end side of the flange.
The other end face is arranged at an intermediate position between the apex of the corner portion of the joint portion and the R stop of the corner portion including the apex, and welded to the side surface of the joint portion. Joined,
The gap between the end surface on one end side of the flange to which the horizontal haunch is welded and the side surface of the joint portion is formed based on the difference between the outer diameter of the joint portion and the width of the flange portion. A column-beam joint structure characterized by this. The pillar portion and the joint portion are
It is molded so that the ratio of the outer diameter B of the pillar portion to the plate thickness tp of the joint portion is 10 ≦ B / tp ≦ 15.
The column-beam joining structure according to claim 1, wherein the outer radius of curvature of the corner portion of the joint portion is formed to be 1.5 to 2.5 times the plate thickness of the joint portion.

Images